Successful modification | The parasite was generated by the genetic modification |
The mutant contains the following genetic modification(s) |
Gene disruption,
Introduction of a transgene,
Introduction of a transgene
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Reference (PubMed-PMID number) |
Reference 1 (PMID number) : 28481199 |
MR4 number |
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Parent parasite used to introduce the genetic modification |
Rodent Malaria Parasite | P. berghei |
Parent strain/line | P. berghei ANKA |
Name parent line/clone |
P. berghei ANKA 820cl1m1cl1 (RMgm-164)
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Other information parent line | P. berghei ANKA 820cl1m1cl1 (RMgm-164) is a reference ANKA mutant line which expresses GFP under control of a male and RFP under control of a female gametocyte specific promoter. This reference line does not contain a drug-selectable marker (PubMed: PMID: 19438517). |
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The mutant parasite was generated by |
Name PI/Researcher | Fang H, Brochet M |
Name Group/Department | Department of Microbiology and Molecular Medicine |
Name Institute | University of Geneva |
City | Geneva |
Country | Switzerland |
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Name of the mutant parasite |
RMgm number | RMgm-4145 |
Principal name | SOC2-KO |
Alternative name | |
Standardized name | |
Is the mutant parasite cloned after genetic modification | Yes |
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Phenotype |
Asexual blood stage | Reduced growth/multiplication of asexual blood stages. |
Gametocyte/Gamete | Strongly reduced exflagellation (male gamete formation). Reduced DNA replication during male gamete formation (mainly blocked at 2N; proportions of haploid microgametocytes in 10 min activated microgametocytes were similar in the KO and its WT counterpart indicating that SOC2 is not required for initiation of DNA replication and DNA replication per se. However, 47% of the parasites remained diploid and 20% and 16% reached the 4N and 8N levels, respectively.
Strongly reduced mitotoic spindle formation in microgametocytes at 10 min. after activation. Normal axoneme in microgametocytes at 10 min. after activation. |
Fertilization and ookinete | Strongly reduced exflagellation (male gamete formation). Reduced DNA replication during male gamete formation (mainly blocked at 2N; proportions of haploid microgametocytes in 10 min activated microgametocytes were similar in the KO and its WT counterpart indicating that SOC2 is not required for initiation of DNA replication and DNA replication per se. However, 47% of the parasites remained diploid and 20% and 16% reached the 4N and 8N levels, respectively.
Strongly reduced mitotoic spindle formation in microgametocytes at 10 min. after activation. Normal axoneme in microgametocytes at 10 min. after activation. |
Oocyst | Not tested |
Sporozoite | Not tested |
Liver stage | Not tested |
Additional remarks phenotype | Mutant/mutation
The mutant lacks expression of SOC2 and expresses RFP and GFP in female and male gametocytes, respectively.
Protein (function)
The protein is identified in a screen for proteins that are phosphorylated by CDPK4.CDPK4 has an essential role in male (micro)gamete formation (exflagellation).
Among these proteins, it was decided to name those without predicted function SOC, for substrate of CDPK4. Ten proteins were indeed conserved Plasmodium proteins of unknown function and one protein, SOC2, was annotated as cyclin-related protein 2 but it was suggested be unrelated to cyclins. Also GAP40 was identified.
To investigate the roles of SOC1 to 4 and GAP40 during gametogenesis, it was attempted to individually knock-out their encoding proteins. As controls, soc5 and soc6 were included that were not differentially phosphorylated in a CDPK4-KO mutant. For gap40 no transgenic parasites could be obtained. Viable KO parasites could be detected in mixed asexual stages for six genes and non-clonal populations were first assessed for microgametocyte DNA replication and exflagellation. No defects were observed in the SOC4-KO line as well as in the SOC5-KO and SOC6-KO control lines suggesting that these proteins do not represent crucial CDPK4 effectors in the regulation of male gametogenesis. Defects in DNA replication or exflagellation were observed for SOC1-KO, SOC2-KO, and SOC3-KO lines that were cloned for in depth characterisation.
Phenotype
Reduced growth/multiplication of asexual blood stages.
Strongly reduced exflagellation (male gamete formation). Reduced DNA replication during male gamete formation (mainly blocked at 2N; proportions of haploid microgametocytes in 10 min activated microgametocytes were similar in the KO and its WT counterpart indicating that SOC2 is not required for initiation of DNA replication and DNA replication per se. However, 47% of the parasites remained diploid and 20% and 16% reached the 4N and 8N levels, respectively.
Strongly reduced mitotoic spindle formation in microgametocytes at 10 min. after activation. Normal axoneme in microgametocytes at 10 min. after activation.
This 623 kDa protein appeared to be specific to Plasmodium and is predicted to encode six transmembrane domains and six sialidase penultimate C-terminal domains. C-terminal 3xHA tagging of SOC2 only allowed detection of a c.a. 140 kDa protein. Immunoprecipitation of SOC2-3xHA recovered peptides mapping on the last 1,137 amino acids suggesting SOC2 is processed into at least two different isoforms. The 3xHA tagged C-terminal end of SOC2-3xHA was found to colocalise with mitotic spindles further suggesting a role in their assembly
Additional information
Other mutants |